This invention relates to a lens housing container for housing a lens having a flange portion formed along the edge of the main body of the lens.
In recent years, accompanied by the optical disk device becoming of high precision and compact, the thickness and the outer size of a lens for use in an optical pickup has become remarkably small.
Accordingly, it has been proposed to set a lens in a form housed in such a lens housing container as shown in FIG. 6 and FIG. 7 to a lens fitting device.
In these drawings, a plurality of cylindrical-shaped lens housing portions 1013 are formed in the long carrier tape 1010 by using a thermal forming method for example.
On the other hand, the lens 1001 is composed of the lens main body 1003 and the flange portion 1005 formed along the edge of the lens main body 1003, and the lens surfaces 1007 and 1007xe2x80x2 project out of the ring-shaped surfaces 1009 and 1009xe2x80x2 of the flange portion 1005.
In the lens housing portion 1013 of the carrier tape 1010, the lens 1001 is housed in such a manner that it comes to the opening side the lens surface 1007 which projects out of the ring-shaped surface 1009 of the flange portion 1005 of the lens 1001, and the supporting portion 1015 for supporting the ring-shaped surface 1009xe2x80x2 of the flange portion 1005 of the lens 1001 at the reverse side to the opening is formed in order not to make the other lens surface 1007xe2x80x2 come into contact with the carrier tape.
Further, the housing portion is designed in such a manner that the depth from the supporting portion 1015 of the lens housing portion 1013 of the carrier tape 1010 up to the opening is approximately equal to the thickness of the flange portion 1005 of the lens 1001.
Accordingly, when the lens 1001 is housed in the lens housing portion 1013, the lens surface 1007 become projected out of the carrier tape 1010.
Further, by putting the cover tape 1021 so as to cover the opening of the lens housing portion 1013, the flange portion 1007 of the lens 1001 is made to press the supporting portion 1015; thus, in the lens housing portion 1013, it is prohibited that the lens 1001 moves in the optical axis direction, and it is prevented that the lens surface 1007 is flawed by the cover tape 1021.
The carrier tape 1010 having the cove tape 1021 stuck on it is wound onto the reel 1008, and is set in the lens fitting device.
However, in the lens housing container shown in FIG. 6 and FIG. 7, when the carrier tape having the cover tape 1021 stuck on it is wound round, as shown in FIG. 8, the bottom surface of the lens housing portion 1013 of the carrier tape 1010, which is wound around the outer side of the cover tape 1021 with which the lens surface 1007 is in contact, comes into sliding contact with the cover tape 1021, and by the movement of the cover tape 1021 in the direction of winding, it sometimes occurs that the lens surface 1007 of the lens 1001 is flawed.
This invention has been made in view of the above-mentioned problem, and it is an object of the invention to provide a lens housing container which does not make the lens surface flawed when the carrier tape is wound round.
This invention to solve the above-mentioned problem is represented by any one of structures (1) to (8) described below.
Structure (1): A lens housing container for housing a plurality of lenses, comprising a long carrier tape having a supporting portion for supporting one ring-shaped surface of the flange portion of said lens, and a plurality of lens housing portions; and a long cover tape to be stuck on said carrier tape so as to cover said lens housed in said lens housing portion, wherein said supporting portion supports said one ring-shaped surface of said flange portion of said lens, so as not to come into contact with said one lens surface of said lens, said lens housing portion houses said lens so that a part of the other lens surface of said lens is projected from or is flush with the upper surface of said carrier tape, said cover tape restrains said lens housed in said lens housing portion from moving in the optical axis direction, said carrier tape has projections, and in order to make a clearance, in the state that said carrier tape having said cover tape stuck on it is wound round, between the portion of the cover tape facing said other lens surface of said lens housed in said lens housing portion and the portion of said carrier tape which is wound outside it, said projections of said carrier tape which is wound outside come into contact with the portion of the carrier tape or the cover tape which is wound inside.
Structure (2): The lens housing container as set forth in structure (1), wherein the aforesaid cover tape is in contact with the other surface of the lens housed in the lens housing portion.
Structure (3): The lens housing container as set forth in structure (1), wherein the projections are formed in the outer side area of a tangent which is tangent to the circular edge of the other lens surface of the lens to be housed and is parallel to the direction of winding of the carrier tape.
Structure (4): The lens housing container as set forth in structure (1), wherein the height of the projections is equal to or larger than the sum of the projection amount of the housing portion from the carrier tape and the projection amount of the other lens surface of the lens from the other ring-shaped surface of the flange portion.
Structure (5): The lens housing container as set forth in structure (1), wherein the projections are provided on the back surface of the lens housing portions.
Structure (6): The lens housing container as set forth in structure (1), wherein any two projections which are adjacent to each other in the winding direction among the projections have different cross-sectional shapes in the direction perpendicular to the height direction of the projections respectively.
Structure (7): The lens housing container as set forth in structure (1), wherein any two projections which are adjacent to each other in the winding direction among the projections are located at different positions with respect to said lens housing portions.
Structure (8): The lens housing container as set forth in structure (1), wherein the lens is a plastic lens.
Another preferable structures (9) to (14) of the present invention are as follows.
Structure (9) is a lens housing container comprising a long carrier tape having a plurality of lens housing portions having a supporting portion for supporting one ring-shaped surface of the flange portion of a lens formed so as not to make one surface of the lens come into contact with the bottom of the housing portion, in such a manner as to make a part of the other lens surface of said lens housed project out of or become flush with the upper surface of said carrier tape, and a long cover tape to be stuck on said carrier tape so as to cover the lens housed in the housing portion, and restraining said lens from moving in the optical axis direction by said cover tape, wherein, in order to make a clearance, in the state that said carrier tape having said cover tape stuck on it is wound round, between the portion of the cover tape facing the other lens surface of the lens housed in said lens housing portion and the portion of the carrier tape which is wound outside it, projections coming into contact with the portion of the carrier tape or the cover tape which is wound inside are formed on said carrier tape.
In order to make a clearance, in the state that said carrier tape having said cover tape stuck on it is wound round, between the portion of the cover tape facing the other lens surface of the lens housed in said lens housing portion and the portion of the carrier tape which is wound outside it, by forming projections coming into contact with the portion of the carrier tape or the cover tape which is wound inside on said carrier tape, the lens surface is not flawed when said carrier tape having said cover tape stuck on it is wound round.
In addition, in this invention, the flange portion means not only the portion which is definitely different in shape from the lens main body as shown in FIG. 2, but also the portion which is capable of being used optically but not to be used optically when it is actually mounted in a device or the like.
Structure (10) is a lens housing container as set forth in structure (9) wherein the aforesaid projections are formed in the outer side area of a tangent which is tangent to the circular edge of the other lens surface of the lens to be housed and is parallel to the direction of winding of said carrier tape.
By forming the projections at the outer side of a tangent which is tangent to the circular edge of the other lens surface of the lens to be housed and is parallel to the direction of winding of said carrier tape, it never occurs that the projections come into contact with the portion of the cover tape facing the other lens surface when the tape is wound round, and the lens surface is never flawed.
Structure (11) is a lens housing container as set forth in structure (9) wherein the height of the aforesaid projections is equal to or larger than the sum of the projection amount of the aforesaid housing portion from the carrier tape and the projection amount of the other surface of said lens from the other ring-shaped surface of the aforesaid flange portion.
By making the height of the aforesaid projections equal to or larger than the sum of the projected amount of aforesaid housing portion from the carrier tape and the projected amount of the other surface of said lens from the other ring-shaped surface of the aforesaid flange portion, the portion of the cover tape facing the lens surface does not come into contact with the bottom surface of the lens housing portion of the carrier tape wound outside it; therefore, the lens surface is not flawed.
Structure (12) is a lens housing container as set forth in structure (9) wherein the aforesaid projections are provided on the bottom surface of the aforesaid lens housing portions.
By providing said projections on the bottom surface of said lens housing portions, the clearance between the portion of the cover tape facing the other lens surface of the lens housed in said lens housing portion and the carrier tape which is wound outside it can be set at a small value.
Structure (13) is a lens housing container as set forth in structure (9) wherein the aforesaid projections are of at least any one of two kinds of projections, one of which is such one that any two projections which are adjacent to each other in the winding direction have different cross-sectional shapes in the direction perpendicular to the height of said projections respectively, and the other of which is such one that any two projections which are adjacent to each other in the winding direction are located at different positions with respect to said lens housing portions.
By making the projections be of at least any one of two kinds of projections, one of which is such one that any two projections which are adjacent to each other in the winding direction have different cross-sectional shapes in the direction perpendicular to the height of said projections respectively, and the other of which is such one that any two projections which are adjacent to each other in the winding direction are located at different positions with respect to said lens housing portions, the probability of one projection fitting into another projection is reduced when the carrier tape is wound round.
As a lens that is suitable to be housed in a lens housing container as set forth in any one of Structures (9) to (13), a plastic lens of structure (14) which is easy to flaw if it is handled without care can be cited.
In addition, this invention should not be confined to a plastic lens, but it is needless to say that a lens housing container of this invention can be applied to a glass lens.